to john mcmillan



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W. LAWRIE 8v J. MCMILLAN.

PURNAGB.

110.421.589. Patented Feb. 18,1890.

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UNITED STATES APATENT OFFrcE.

VILLIAMLAWRIE AND J OI-IN MCMILLAN ASSIGNORS, BY IWIESNE ASSIGNMENTS,SAME PLACE.

, OF PETROLIA, ONTARIO, CANADA, TO JOHN MCMILLAN, TRUSTEE, OF

FU RNACE.

SPECIFICATION forming part of Letters Patent N o. 421,589, datedFebruary 18, 1890.

Application filed J auuary 2.4, 1889. Renewed January 13, 1890.' SerialNo. 336,718. (No model.)

To all whom it may concern'.-

Be it known that we, VILLIAM LAWRIE and JOHN MCMILLAN, citizens of theDominion of Canada, residing at Petrolia, in the county of Lambton andProvince of Ontario,

Canada? have invented certain new and useful Improvements in Furnaces,of which the following is a specification.

Our invention relates to that class of fur- Io naces designedmoreparticularly forburning gas or liquid fuel 5 and it consists in anovel construction and arrangement of the iiues thereof, whereby thecombustion is rendered thorough.

In the accompanying drawings, Figure l is a front face view of ourimproved furnace; Fig. 2, a transverse vertical sectional view of thesame; Figs. 3, 4, 5, and 6, horizontal views on the lines w y y, z e',and w w, respect- 2o ively; and Fig. 7, avertical longitudinal sectionalview through the center of the furnace on the line 7 7.

While in the drawings we have shown the invention as applied to theheating of a z 5 steam-boiler, it is apparent that it is also applicableto oil-stills, whether horizontal or vertical, or lfor any otherpurposes where high temperature is required. v

In carrying out our invention we heat the 3o air before admitting it tothe combustionchamber, and also superheat the steam by which thehydrocarbon gas or other liquid fuel is injected, thereby insuring athorough commingling of the particles of air, steam,

3 5 and oil or gas, and a consequent economization of fuel and theproduction of an intense heat.

A indicates the furnace as a whole, provided at its rear with an openingor inlet B.

4o Extending along the iioor parallel with the side wallsA of thefurnace are partitions C C, which extend nearly to the front wall of thefurnace and terminate a short distance therefrom to form passages D, thesaid partitions O dividing the floor-space of the furnace into threechambers E, F, and G, as shown in Figs. 2, 3, and 7. The partitions Cwill be made of nre-brick or other heat-resisting substance, and thetops ofthe fines or passages E F G 5o thus formed will be made offire-clay or other suitable material. Directly above'the passages orchambers E F Gare similarpassages H, I, and J, the first and last ofwhich communicate with the iiues E and G at the rear end of the latterthrough openings K, formed by the roofs or covers of the ilues E G,stopping short of the rear end of the furnaces, as shown in Figs. 4 and7. Directly over the partitions O are similar partitions L, which extendfrom the rear of the furnace-wall 6o nearly to the front and separatethe chambers H, I, and J, except at the front end, where by formingrecesses M inv the front wall of the furnace communication isestablished between the flues or passages HJ 'and 65 the central flue orpassage I. It is not essential lthat the front Wall of the furnace berecessed, as sh'own in Fig. 4, as it is apparent that the partitions Lmay terminate a distance therefrom in a manner similar to the parti-V 7otions O. (Shown in Fig. 3.)

The top of the combustionchamber I is covered by means of an arch N(shown in Figs. 2, 6, and 7) and communicates at the rear end of thefurnace with the space bel neath the boiler by means of an opening O,formed through the arch, as shown in Figs. 6 and 7. From thisarrangementit will be seen that the air entering at the rear end of thefurnace through the central iiue F, passes for- Se ward to the front endthereof, thence through openings or passages D into the iiues E andGback to the rear end of the furnace, up through openings K into theflues or passages H J, thence forward again to the front end of thefurnace, thence, by means of passages Min the front wall of the furnace,into the front end of the central mixing-chamber I toward the rear endof the furnace, and finally up through the opening O into the 9oheating-chamber P.

The top of lthe flues H and J are provided with covers which extend fromend to end of the furnace, thereby forming chambers or pockets Q, whichare closed on all sides, as shown in Figs. 2 and 5.

R indicates a steam-pipe extending from the dome of the boiler into oneof the pock ets or chambers Q, as shown in Figs. 2 and 5,

the said pipe traversing the length of the roo chamber one or more timesand extending to the opposite side of the furnace, where 1t traverses ina similar manner the other pocket Q. After leaving the pocket Q the pipepasses out at the front Wall of the furnace and re-enters the same atthe front end of the mixing or combustion chamber I, as shown in Figs.l, 4, and 7, Where it is provided with an injector-burner of anysuitable construction, by means of which the liquid fuel or gas isinjected into the mixing-chamber. It will be noticed from thisconstruction that the steam will be highly superheated, and that as itissues from the pipe Q into the mixing-chamber I it will suck or draw inthrough the opening in the front end of said chamber a large quantity ofair which has become heated by its circuitous travel through the fluesE, F, G, I-I, I, and J. By making the mixingchamber I comparativelysmall the liame from the injector-burner is caused to impinge on thelire-brick or fire-clay linings or covers of the air-lines, therebysplitting up the hydrocarbon into minute particles and mixing itthoroughly with the heated air, tbc., and producing practically completecombustion and a saving of fuel over prior plans.

IVe are aware that it is not broadly new to cause the air to travelcircuitously, and thereby become heated before being delivered into thecombustioil-chamber.

Having thus described our invention, what We claim isl. In a furnace,the combination, With the central air-inlet flue F and the return-finesE G, communicating therewith, of the flues II J, located above andcommunicating with the rear ends of the flues E G, a mixingchainber I,located directly over the flue F an communicating at its forward endwith the lues II J, a chamber I) above the chamber I, and an arch N,covering chamber I provided with an opening O, all substanf as shown.The furnace A, provided With central passage F, return-passages E G,communicating with passage F at the front of the Vfurnace by openings DD, dues or passages I-I I J directly above the llues E F G, openings KK, connecting th'e rear ends of the lues E' G and II J, and openings MM, connecting the passages II and J with the passage I at the front endof the latter, and

an outlet C) at the rear end of the passage I. 3. The furnace A,provided with the airinlet flue F, return-flues E, G, II, and J, eon

necting at alternate ends and causing a eircuitous travel of the air,the mixing-chamber I, receiving the heated air from the fines II J, andan injector-burner projecting. into 6o the end of the mixing-chamber,whereby the air, steam, and oil or gas are thoroughly mixed and perfectcombustion secured.

Li. In a furnace, the combination, with the main body having anair-inlet B, of the short 6 5 partitions C C, dividing the floor-spacein-to flues E, F, and G, the latter' E G connecting with the former F bypassages D D, covers for said iiues E F G, partitions Il, dividing thespace above the flues E F G into similar 7o flues II I J two of which IIand J communicate with the line I and the flues E G, an outlet in fiueor chamberI, and an injector-burner extending into the chamber I, allsubstan tially as shown.

5. In a furnace for burning hydrocarbons or other liquid fuels, thecombination, with the mixing-chamber I, of the closed pockets Q Q, andthe steam-pipe passing throughsaid pockets and serving to deliversuperhcated 8o steam to the injector-burner.

(. In a furnace, the combination, with the communicating passages E F Gand II I J, ar-

ranged in two series, one above the other,

and having their walls made of nre-clay or 35 other heat-resistingsubstance, of the poele ets Q Q and the injector-burner extending intothe chamber or passage I.

'7. In a furnace of the class described, the

combination, with the recessed front wall, of 9o the mixing-chamber I,provided 'with an opening in its front end and adischarge-opening at itsrear, the air-fines on each side of the mixing-chamber communicatingtherewith,

and an injector-burner extending into the open end of themixing-ehamber- S. In a furnace for burning liquid fuel or gas, thecombination, with the mixing-chamber provided with an injector-burnerand with openings around said burner, ol' a se` ries of fines orpassages within the furnace communicating with the mixing chamberthrough the openings thercin,whereby heated air is delivered into themixing-chamber.

In witness whereof we hereunto set our hands in the presence of twowitnesses.

WILLIAM LAWRI'E. JOHN MCMILLAN. Witnesses:

1I. J. DAWSON, WM. J. CLARKE.

IOO

